Dynamic Metasurfaces Using Phase-Change Chalcogenides

Metasurfaces have attracted increasing attention and provide promising solutions for cost-effective and highly efficient optics due to their unprecedented capabilities in light manipulation. In recent years, phase-change materials (PCMs), especially phase-change chalcogenides, are integrated into metasurfaces to explore innovative configurations exhibiting remarkable tunability and reconfigurability due to the dramatic optical contrasts available in PCMs along with their high chemical and long-term stability and high switching speeds. In this review, the current achievements and ongoing developments in dynamic metasurfaces based on phase-change chalcogenides, an emerging field in nanophotonics and optoelectronics, are outlined. Starting with the basic material properties of phase-change chalcogenides, the structural transformations and dielectric functions of two main chalcogenides are described. This is followed by an overview of the main progress in typical dynamic metasurfaces based on phase-change chalcogenides enabling global and local amplitude/phase modulation. The review ends with a short conclusion and outlook on possible future developments.